This is a test of Wavr, the Wordpress plugin for embedding Google Waves. You may not see anything if you don’t have a Wave account. It’s now working for me at least. (Two tricks were needed: make the wave public, and un-urlencode the + in the Wave id).
If you have a Wave account, the grey box above is editable just like at the Wave site: you can add to the Wave by clicking on the bottom border of the current wave, or use the down-arrow at the right to select edit options. Wave itself is at https://wave.google.com/wave/#restored:wave:googlewave.com!w%252B0tVPqpaUA.1 ; I assume you can add yourself to it there. You should then be able to see live updates when you edit the Wave either in your Wave home page or here.